Theoretical physicist Stephen Hawking will appear on an upcoming episode of 'The Big Bang Theory'.
CBS has confirmed that Hawking will appear on the April 5 episode in a scene with Sheldon (Jim Parsons) after his character has a run in with the famous physicist.
"When people would ask us who a 'dream guest star' for the show would be, we would always joke and say Stephen Hawking – knowing that it was a long shot of astronomical proportions," says executive producer Bill Prady.
"In fact, we're not exactly sure how we got him. It's the kind of mystery that could only be understood by, say, a Stephen Hawking."
Producers had asked Hawking, best known for his best-selling book, 'A Brief History of Time', to appear on the show before, but he had been too ill to take part.
Hawking's appearance will air a week after Leonard Nimoy lends his voice to a dream sequence on the March 29 episode.
The 70-year-old, who suffers from ALS and speaks with the aid of a voice synthesizer, has previously appeared on 'The Simpsons' and even an episode of 'Star Trek: The Next Generation'.